Alert archive / Virginia / Flash Flood Warnings in 2021

Flash Flood Warning 37, NWS Blacksburg, VA

September 22, 20214 counties in Virginia

NWS Blacksburg, VA issued this flash flood warning at Sep 22, 2021, 1:00 AM EDT for 4 counties in Virginia. It was in force for 3 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Sep 22, 2021, 1:00 AM EDT (05:00 UTC)
Expired: Sep 22, 2021, 3:40 AM EDT
In force: 3 hr
Issued by: NWS Blacksburg, VA
Area: Storm-based polygon
Flood severity: None

Counties City of Roanoke, VA, City of Salem, VA, Franklin County, VA, Roanoke County, VA

The radar

The Roanoke radar (KFCX), 35 km from the middle of the area, began a volume at 05:01 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Roanoke, VA (KRNK), launched 00:00Z, 5.0 hours before the alert went out and 52 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 475 m above ground
0-6 km bulk shear: 22 kt
0-1 km storm-relative helicity: 31 m²/s²
0-3 km storm-relative helicity: 211 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

765 
WGUS51 KRNK 220500
FFWRNK
VAC067-161-770-775-221100-
/O.NEW.KRNK.FF.W.0037.210922T0500Z-210922T1100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Blacksburg VA
100 AM EDT Wed Sep 22 2021

The National Weather Service in Blacksburg has issued a

* Flash Flood Warning for...
  Northwestern Franklin County in west central Virginia...
  Roanoke County in west central Virginia...
  The City of Roanoke in west central Virginia...
  The City of Salem in west central Virginia...

* Until 700 AM EDT.

* At 100 AM EDT, Rainfall was increasing across the warned area as a 
  band of moderate to heavy rain develops to the south of the warned 
  area and will move north through the warned area during the next 
  several hours. In prior hours, 2 to 3 inches of rain  has already 
  fallen in parts of the warned area, including Roanoke City, Salem 
  City, and Roanoke County. Additional rainfall of 2 to 3 inches 
  during the next six hours is likely.  Flash Flooding is imminent.

  HAZARD...Flash flooding caused by heavy rain.

  SOURCE...Radar.

  IMPACT...Flash flooding of small creeks and streams, urban
           areas, highways, streets and underpasses as well as
           other poor drainage and low-lying areas.

* Some locations that will experience flash flooding include...
  Roanoke...                         Salem...
  Vinton...                          Rocky Mount...
  Boones Mill...                     Bent Mountain...
  Catawba...

This includes the following locations...
	The Salem Fairgrounds and Roanoke Regional Airport.

This includes the following streams and drainages...
  Blackwater River, Back Creek and Big Bear Rock Branch.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

Be especially cautious at night when it is harder to recognize the 
dangers of flooding.

When it is safe to do so, please send your reports of flooding, 
including mudslides or flooded roads, to the National Weather 
Service by calling toll free at 1...8 6 6...2 1 5...4 3 2 4. Reports 
and pictures can also be shared on the National Weather Service 
Blacksburg Facebook page and on Twitter.

&&

LAT...LON 3736 8022 3738 8019 3738 8015 3742 8006
      3740 8006 3733 7987 3702 7986 3702 8006

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL...1-2 INCHES IN 1 HOUR

$$

RAB

2 follow-up statements

381 
WGUS51 KRNK 220526
FFWRNK
VAC067-161-770-775-221700-
/O.EXT.KRNK.FF.W.0037.000000T0000Z-210922T1700Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service BLACKSBURG VA
126 AM EDT Wed Sep 22 2021

The National Weather Service in BLACKSBURG has extended the

* Flash Flood Warning for...
  Roanoke County in west central Virginia...
  The City of Salem in west central Virginia...
  The City of Roanoke in west central Virginia...
  Northwestern Franklin County in west central Virginia...

* Until 100 PM EDT Wednesday.

* At 100 AM EDT, Rainfall was increasing across the warned area as a 
  band of moderate to heavy rain develops to the south of the warned 
  area and will move north through the warned area during the next 
  several hours. In prior hours, 2 to 3 inches of rain  has already 
  fallen in parts of the warned area, including Roanoke City, Salem 
  City, and Roanoke County. Additional rainfall of 2 to 3 inches 
  during the next six hours is likely.  Flash Flooding is imminent.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Radar indicated.

  IMPACT...Flooding of small creeks and streams, urban areas, 
           highways, streets and underpasses as well as other 
           drainage and low lying areas.

* Some locations that will experience flooding include...
  Roanoke...
  Salem...
  Vinton...
  Boones Mill...
  Catawba...
  Bent Mountain...
  and Hollins.

This includes the following streams and drainages... White Oak 
Creek, Gum Spring Branch, South Fork Roanoke River, Roanoke River 
and Back Creek.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.

Be especially cautious at night when it is harder to recognize the
dangers of flooding.

When it is safe to do so, please send your reports of flooding,
including mudslides or flooded roads, to the National Weather Service
by calling toll free at 1...8 6 6...2 1 5...4 3 2 4. Reports and
pictures can also be shared on the National Weather Service
Blacksburg Facebook page and on Twitter.

&&

LAT...LON 3736 8022 3738 8019 3738 8015 3742 8006
      3740 8006 3733 7987 3702 7986 3702 8006

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL...1-2 INCHES IN 1 HOUR

$$

RAB

910 
WGUS71 KRNK 220740
FFSRNK

Flash Flood Statement
National Weather Service Blacksburg VA
340 AM EDT Wed Sep 22 2021

VAC067-161-770-775-220750-
/O.CAN.KRNK.FF.W.0037.000000T0000Z-210922T1700Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Franklin VA-Roanoke VA-City of Roanoke VA-City of Salem VA-
340 AM EDT Wed Sep 22 2021

...FLASH FLOOD WARNING IS CANCELLED FOR NORTHWESTERN FRANKLIN AND 
ROANOKE COUNTIES AND THE CITY OF ROANOKE AND THE CITY OF SALEM...

The heavy rain has ended. Flooding is no longer expected to pose a 
threat. Please continue to heed remaining road closures.

A Flash Flood Watch remains in effect until 800 AM EDT Thursday for 
portions of North Carolina and Virginia.

LAT...LON 3736 8022 3738 8019 3738 8015 3742 8006
      3740 8006 3733 7987 3702 7986 3702 8006

$$

RAB

The office that day

Everything else NWS Blacksburg, VA issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Sep 21, 8:07 PM EDT	Areal Flood Advisory	RNK	Floyd, Franklin	3 hr
Sep 21, 9:00 PM EDT	Areal Flood Advisory	RNK	Floyd, Franklin, Montgomery, Roanoke, City of Roanoke, City of Salem	3 hr
Sep 21, 9:34 PM EDT	Areal Flood Advisory	RNK	Carroll, Floyd, Patrick	3 hr
Sep 21, 10:10 PM EDT	Flash Flood Warning	RNK	Carroll, Floyd, Patrick	6 hr
Sep 21, 10:19 PM EDT	Areal Flood Advisory	RNK	Floyd, Patrick	3 hr
Sep 21, 11:25 PM EDT	Areal Flood Advisory	RNK	Floyd, Franklin	3 hr
Sep 21, 11:56 PM EDT	Areal Flood Advisory	RNK	Carroll, Floyd, Montgomery, Pulaski, City of Radford	6 hr
Sep 22, 12:20 AM EDT	Flash Flood Warning	RNK	Floyd, Patrick	4 hr
Sep 22, 1:12 AM EDT	Flash Flood Warning	RNK	Montgomery	6 hr
Sep 22, 2:27 AM EDT	Flash Flood Warning	RNK	Craig, Giles	6 hr
Sep 22, 5:03 AM EDT	Areal Flood Advisory	RNK	Floyd, Franklin, Henry, Patrick	3 hr
Sep 22, 11:00 AM EDT	Areal Flood Advisory	RNK	Bedford, Botetourt, Floyd, Franklin, Henry, Patrick and 7 more	11 hr
Sep 22, 1:35 PM EDT	Special Weather Statement	RNK	City of Martinsville	25 min
Sep 22, 2:02 PM EDT	Special Weather Statement	RNK	Amherst	28 min
Sep 22, 2:52 PM EDT	Areal Flood Advisory	RNK	Craig, Giles, Montgomery, Pulaski, City of Radford	2 hr
Sep 22, 3:38 PM EDT	Special Weather Statement	RNK	Floyd, Montgomery	22 min
Sep 22, 4:01 PM EDT	Special Weather Statement	RNK	Patrick	29 min
Sep 22, 4:20 PM EDT	Special Weather Statement	RNK	Patrick	40 min
Sep 22, 4:27 PM EDT	Severe Thunderstorm Warning	RNK	Patrick	33 min
Sep 22, 4:35 PM EDT	Special Weather Statement	RNK	Franklin	40 min
Sep 22, 4:47 PM EDT	Special Weather Statement	RNK	Rockbridge, City of Buena Vista, City of Lexington	28 min
Sep 22, 4:53 PM EDT	Flash Flood Warning	RNK	Bedford, Franklin, Patrick, Roanoke	4 hr
Sep 22, 5:32 PM EDT	Flash Flood Warning	RNK	Bedford, Botetourt, Rockbridge, City of Buena Vista, City of Lexington	3 hr
Sep 22, 7:10 PM EDT	Areal Flood Warning	RNK	Rockbridge	2 hr
Sep 22, 7:19 PM EDT	Areal Flood Advisory	RNK	Amherst	3 hr

Nearby

Flash Flood Warnings in Virginia, 2021 Every flash flood warning in 2021

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.